Method of fungusproofing textiles



Fatented! Aug. li t, 31%45 2,381,863 METHOD OF FUNGUSPROOFING TEXTILESPaul George Benignus, Bellevllle, lll., assignor to Monsanto ChemicalCompany, St. Louis, Mo., a corporation of Delaware No Drawing.Application May 1, 1943, Serial No. 485,341

2 Claims.

This invention relates to fungicides for rendering textiles permanentlyresistant to fungus attack and more particularly to the fungus-proofingof textiles with copper salt derivatives of 8-hydroxy quinoline.

It is known that 8-hydroxy quinoline (oxy quinoline) and B-hydroxyquinoline sulfate (quinosol) possess preservative properties. Forexample, United States Patent No. 575,978 issued to Ostermann disclosedthis characteristic of 8- hydroxy quinoline. In addition,8-hydroxyquinoline, its oil-soluble salts, such as the benzoate andpalmitate, or groups substituted for the hydrogen atom, were suggestedin United- States Patent No. 2,021,137 issued to Stone for use inwater-proof coatings for fibrous materials to render them antiseptic aswell as water-proof. The preparation of the copper salt of, 8-hydroxyquinoline as an analytical reagent has been disclosed in the art.Inorganic heavy metal salts have been employed in the treatment ofcellulose fibers for various purposes, such as fire-proofing,waterproofing and preservation. A large ratio of heavy metal to treatedfibrous material had to be established to provide even a moderate degreeof preservative action. Moreover, the treatment was not enduring,apparently because the heavy metal impregnant lacked the stability andresistance to removal by water and aqueous solutions under conditionsnormally encountered in the atmospheric weathering of textiles.

One of the objects of the present invention is to provide textilespermanently fungicide-impregnated with copper salt derivatives of8-hydroxy quinoline.

Another object is to provide fungus-proofed textiles characterized byimproved resistance to removal of the fungicide agent by water andaqueous solutions in the normal weathering of the impregnated material.

A further object is to provide a method for permanently fungus-proofingfibrous organic materials with copper salt derivatives of 8-hydroxyquinollne.

A further object is to provide a fungus-proofing impregnating agent fortextiles characterized by the property of imparting a permanently highdegree of resistance to fungal growth together with a low ratio of heavymetal to textiles.

Further objects will'become apparent from the following description ofthe invention.

According to the present invention generally stated, textiles, such ascotton fabrics, duck, osnaburg, twine and cord, are renderedfungus-proof by impregnation with copper salt derivatives of 8-hydroxyquinolinel This impregnation may be accomplished in several ways. Forexample, the textile, such as cotton duck or khaki, may be soaked in anaqueous solution of a copper salt, such as the acetate, sulfate or otherwater-soluble copper salt. After impregnation is accomplished to thedesired extent, the textile maybe removed from the solution, renderedfree of excess salt solution, if desired, and transferred to a solutioncontaining B-hydroxy quinoline, desirably present as the acetate,sulfate, phosphate or other acid salt. Following this treatment, thetextile is removed from the solution, excess solution is expelled fromthe textile by any suitable means, for example, pressure rollers, andthe treated textile is dried or washed and dried, as desired. Textilestreated by this process have been found to resist fungus attack underdrastic conditions, such as dampness, exposure to fungus attack,abrasion and repeated and prolonged washings with water and with soaps.It has been found unnecessary to dry the textile immediately upon itsremoval from the 8-hydroxy quinoline solution in order to fix or set thefungicide-impregnant in the textile. The textile may be washed withwater or soap and water while still wet from the treating solutionwithout danger of substantial removal of the fungicide from the textile.

As an alternative to the foregoing procedure, the textile may be treatedin a single-stage with an aqueous solution of the copper saltderivatives of B-hydroxy quinoline in which the salt derivatives aremade soluble by reducing the pH of the aqueous solution to a pH withinthe range of 2.7 to 2.2, or lower. For example, a 0.1N hydrochloric acidsolution, which has a pH of about 1.0 may be used to dissolve solidcopper 8-hydroxy quinoline and the solution thus formed may be employedto impregnate the textile. Acid solutions having a pH value below thatof 0.1N hydrochloric acid may be employed, care being taken, however, toavoid concentrations of acid which will impair the strengthcharacteristics of the textile for a given purpose. This may beaccomplished by mixing an acid, such as dilute hydrochloric acid, with asuspension of the copper salt derivatives of 8-hydroxy quinoline inwater. The conditions under which impregnation is effected with thesolubilized salt derivatives may be varied. For example, theimpregnation may consist of a simple washing operation at room orelevated temperatures or, if desired, a boiling operation followed by alowering of the temperature of the impregnation solution to a pointbelow the boiling point of the solution. After the impregnation has beeneffected to the desired extent, the pH of "the solution is raised to apoint above 2.7, for example, by adding ammonium hydroxide or any othersuitable alt-- hall or alkaline material, such as sodium hydroxide orsodium carbonate. It is to be understood that this elevation of the pHto a point above the pH of 2.7 is for the purpose of rendering thecopper salt derivatives of 8-hydroxy quinoline present on the textilefibers and within the interstices of the fibers insoluble in water oraqueous solutions having a pH in the range of 2.8 to l3. For thispurpose, it is only necessary to add sufllcient alkali to neutralizesumcient of the acid present in the impregnating solution to raise thepH to a point above 2.7. After the copper salt derivatives of S-hydroxyquinoline have been insolubilized within the interstices of the textile,the textile may be removed from the bath, excess liquid may then beexpelled and the textile may be dried. The insolubilization treatmentmay be carried out in an alkaline bath apart from the impregnation bath.

As a further alternative method, analogous in part to the procedurefirst hereinbet ore described, namely, the Z-stage procedure, in placeof an acid salt solution of 8-hydroxy quinoline, the free-base 8-hydroxyquinoline may be employed by using an organic solvent for the base in.place of water. The organic solvent selected may be miscible orimmiscible with water. As an alternative, the free base may beemulsified with water at temperatures above 75-76 C., the melting pointof 8-hydroxy quinoline, and the fabric which has been impregnated withcopper salt solution may be placed in the emulsion.

The process of the present invention may be employed in the treatment oftextiles of many varieties, including twines and cords and fabrics ofthe close-mesh as well as loose-mesh types. The textiles may be composedof cotton, Wool, silk, cellulose derivatives or mixtures of any ofthese. The treatment should be applied in a manner such as to insureuniform impregnation of the textile in order that isolated untreatedportions of the textile may be avoided. The technique of impregnation,as practiced in the textile art and in the art of water-proofing andtreating textiles for various purposes, is understood by those skilledin those arts.

The textiles to be treated by the method of the present invention toprovide the permanently fungus-proof textiles of this invention aredesirably treated in the unsized condition in order to insure suflicientimpregnation of the fibers per se. The textiles may be dyed, bleached orin the natural state. Textiles rendered permanently fungus-proof by theprocess of the present invention may be subsequently dyed. The processof the present invention may be applied advantageously to textiles whichare to be coated or impregnated subsequently, for example, with plasticcompositions containing vinyl resins, styrene resins, cellulose estersor others or other plastic materials.

Textiles which are to be rendered permanently fungus-proof by theprocess of the present invention may be processed by either a batch or acontinuous method. In a. continuous method using the 2-stage process,the textile may be led first through the copper salt bath, thencethrough rollers to expel excess solution and thereafter into a bathcontinuing the acid salt of B-hydroxy suinoline. From this bath, thetextile may be led through. wringer rollers to expel the excesssolution, through. a clear water both, through wringer rollers andthereafter through drying rollers to dry the textile. Prior to immersionin the first bath, the textile may be pre-wetted by immersion in wateror by spraying water upon the material. Various alternative proceduresfor treating textiles by the process of the present invention arecontemplated as part of the pres ent invention.

Textiles rendered fungus-proof by the process of the present inventionare permanently fmigusproof under the most drastic conditions, such ascontact with acid soils, the pH of which ranges from approximately 3.5to e or even somewhat lower. This property is apparently unique withtextiles containing the copper salt derivatives of 8-hydroxy quinoline,since none of the other metal salt derivatives, for example, thealuminum, cadmium, calcium, and magnesium salt derivatives of d-hydroxyquinollne, were found to impart the combination of adequatefungusprooflng and permanency of fungus-proofing to textiles exposed tocontact with moist or wet acid soils. At pH conditions from 2.8 to 4.0,these other salts were solubilized and leached from the textile, therebyexposing the textile to attack by fungus.

The fungus-proof textiles, and the process of rendering textilespermanently fungus-proof, of the present invention are furtherdemonstrated in the following examples, which are to be construed merelyas illustrative of the invention and not as limiting the invention.

Example I An aqueous solution containing 2% of copper acetate wasprepared and heated to 40 C. A test strip of osnaburg fabric measuring6" x 8" was immersed in 400 cc. of this solution and allowed to soak forabout 2-5 minutes with occasional agitation. The fabric was then removedfrom the solution and passed through a winger to remove excess solution.An aqueous solution containing 2.5% of 8-hydroxy quinoline acetate wasprepared and heated to 40 C. The test strip previously impregnated withcopper acetate solution was immersed in 400 cc. of B-hydroxy quinolineacetate solution and allowed to soak for about 2-5 minutes. The fabricwas then removed from the solution, rinsed with tap water and dried.

The treated fabric was scrubbed and washed vigorously and rematedly witha soap containing powdered pumice until the suds remained white. Afterthorough washing in clear water, the fabric was dried and exposed to thetextile rotter, Chaetomium globosum, for 14 days by the method given inCorps of Engineers, U. S. Army Tentative Specification No. T-1452-A,entitled Processing Fabrics, Cordage and Threads for Mildew- Proofing,dated January 15, 1943, paragraphs F-3-a (3) to 3-41 (8), inclusive.There was no evidence of fungus growth on the cloth. An untreatedspecimen exposed under similar conditions was heavily attacked by thefungus.

Another specimen of osnaburg fabric impregnoted in the mannerhereinbefore described was leached in running water for hours, the rateof flow of water through the fabric being about 1 gallon per hour. Afterexposure of the specimen to Chaetomz'um globosum for 14 days, there wasno evidence of fungus growth. The specimen was analyzed for copper andwas found to contain quinoline.

bag.

0.4 4 of the copper salt derivative of.-8-hydroxy Em 1 i A cotton .duckfabric was immersed in. a 1% copper acetate solution at 80 C. for '5-minutes. The fabric was removed from the solution, drained to expelexcess. solution and immersed in a 1.6% solution of 8-'-hydroxy"quinoline acetate-solution T at 70 C. for minutes. '1 The fabricwas remove washed with soap and finally with clear-water and dried.After 14'days of exposure to'Chaetomiam. vglobosum by the method ofExampleI; no evidence of fungus growth.

Example III- A'khaki fabric was immersed in'a 0.5% solution of copperacetate and the solution was'heated to boiling and boiled for 20minutes. Thereupon there was.

with 200 cc. of a 0.1% solution" of d-hydroxy quinoline acetate and.addingsufflcient hydrothe solution was allowed to cool to 50 C. The

fabric was removed, drained and immersed in an 4 0.8% solution of8-hydroxy quinoline acetate for 5 minutes at 40 C. The fabric wasremoved from the solution, washed with soap and water and dried. After14 hours exposure to'Chaetomium globosum by the method of Example I,there was no sign of fungus growth.

Erample IV A piece of twistedcotton cord was immersed in a 0.25%solution of copper nitrate for 30 minutes at room temperature. The cordwas removed,

chloric acid to this mixture to lower the. pH of the solution to 2.4, oruntil the precipitate, which formed upon-mixing the reactants becamesolubilized in the acidic solution. The solution was heated to 40". C.An osnaburg fabric was immersed in the solution for 10 minutes. Afterthis time, suflicient ammonium hydroxide solution was added to raise thepH of the solution to 2.8. The fabric was removed from the solution,drained, washed with soap and water and dried. After inoculation. andincubation with Chaetomium globosum by the method of Exampl I, there wasno evidence of fungus growth on the fabric.

Example VIII An aqueous solution of the copper salt derivatives ofB-hydroxy quinoline was prepared by mixing 200 cc. of an aqueous 2%copper acetate solution with 200 cc. of an aqueous 2.5% a-yhydroxyquinoline acetate solution and adding sufficient hydrochloric acid tolower the pH of the solution to 1.7, or until the precipitate whichformed upon mixing the reactants became solubilized in the 1 acidicsolution. 1 The solution was heated to 50 drained and immersed in a 0.4%solution of 8- hydroxy quinoline sulfate for 5 minutes. The treated cordwas washed with water and dried. After 14 days exposure to Chaetomiumglobosum by the method of Example I, there was no evidence of fungusgrowth on the cord.

Example V fabric. The remainder of the fabric wasexposed to Chaetmniumylobosum. for 14 days in the manner of Example I: there was no evidenceof fungus growth in the fabric.

Example VI A bag of the type used for sand was immersed in a 0.06%solution of copper acetate at C. for 15 minutes. The bag was removedfrom the solution, passed through a wringcr and immersed in a 0.1%solution of B-hydroxy quinoline acetate at 50 C. for 15 minutes. Thetreated bag was removed from the solution, washed with water and dried.Analysis of a specimen of the bag revealed the presence of 0.1% of thecopper salt derivative of 8-hydroxy quinoline in the fabric. The bag wasthen exposed to contact with a wet acid S011 having a pH ofapproximately 3.5-4.0 for several. weeks. The bag was thereupon washedwith water and dried. After inoculation and incubation with Chaetomiumglobosum by the method of Example I, there was no evidence of fungusgrowth on the Example VII An aqueous solution of the copper saltderiva-' C. A cotton duck fabric was immersed in the solution for 10minutes. After this time, the fabric was removed from the solution anddrained free of aqueous solution. .The fabric thus treated was immersedin a 5%.solutionof sodium carbonate for 2 minutes, removed, drained,washed with soap and water and dried. After exposure to Cheetomiumglobosum by the method of Example I, there was no evidence of fungusgrowth on the fabric. 1

It will be observed that the quantity of the copper salt derivative of8-hvdroxy quinoline present in the textiles treated and tested in theexamples hereinbefore described is relatively small and yet there was noevidence of fungus growth when the textiles were subjected to abrasion,washing, leaching and finally to inoculation and incubation withChaetomium globosum by the method of Example I. The permanence andeffectiveness of the treatment are apparent from .this resistance issubstantially of the same degree of permanence as the resistance tofungus attack.

The proportions of copper salt derivative of B-hydroxy quinoline totextile may be varied widely, depending upon the extent of treatmentdesired and the type of service conditions for which the textile isintended. It is evidenced, however, that a minute quantity of thetreating agent in the textile is sufficient under very drasticconditions.

The term textile as employed in describing the present invention isintended to embrace all forms of textile materials, including yarn,twine, cord, rope, fringes and fabrics of various types of weaves, fromclosely woven to loosely woven.

The term copper salt derivatives of 8-hydroxy quinoline" as employed indescribing the present invention is intended to embrace the compoundsformed when a copper salt reacts with B-hydroxy quinoline or its acidsalt. These compounds are most likely to be of the type known as chelatethan one structure can result from the reaction in the practice of thepresent invention, the various structures thus formed are contemplatedas being within the scope oi this invention.

I claim:

1. A process of rendering a textile resistant to attack by moldorganisms which comprises imregnatlng the textile with an aqueoussolution 0! the copper salt derivatives of 8-hydroxy quinoline, saidsalt derivatives being solubilized at a H in the range of 2.2-2.7,subsequently raising the pH 01' the impregnated textile to a DH above2.7, and thereafter washing the treated textile to remove water solublesubstances.

2; A process of rendering atextile resistant to attack by mold organisms'which comprises impregnating the textile with an aqueous solution 0!the copper salt derivatives oi 8-hydroxy quinoline, said saltderivatives being solubilized at a pH below 2.7, subsequently raisingthe pH of the impregnated textile to a pH above 2.7, and there- 10 afterwashing the treated textile to remove water soluble substances.

PAUL G. BENIGNUS.

